Cells taken from the donated eyes of the dead may enable blind people to see the world, a new study has found.

Researchers, who conducted tests on rats, have found that a special kind of human cells found in the back of everyone's eyes could restore partial vision in completely blind rats. Similar results in humans would improve quality of life, but would not give enough vision to read, researchers from the University College London (UCL) said.

Researchers said human trials should begin within three years, the BBC reported.

The research team extracted a special kind of cell called Muller glial cells.

They are a type of adult stem cell capable of transforming into the specialised cells in the back of the eye and may be useful for treating a wide range of sight disorders, researchers said.

"This interesting study shows that Muller glial cells are another viable avenue of exploration for cell therapy in retinal diseases," Dr Paul Colville-Nash from the Medical Research Council, UK, said.

These cells in the laboratory were chemically charmed into becoming rod cells which detect light in the retina. Injecting the rods into the backs of the eyes of completely blind rats partially restored their vision. Brain scans showed that 50 per cent of the electrical signals between the eye and the brain were recovered by the treatment, the report said.

Researchers believe the cells might be able to help patients with disorders such as macular degeneration or retinitis pigmentosa.